Spatio-temporal analysis of renewable energy droughts in Europe: a gridded perspective

The rapid expansion of wind and solar power across Europe is reshaping the structure and operation of the electricity system, with growing emphasis on interconnection and the potential role of a European supergrid. In this context, periods of simultaneously low wind and solar availability, commonly referred to as renewable energy droughts, pose a critical challenge for system reliability and planning. Such events are often assessed at national or regional scales, but these approaches are constrained by geopolitical boundaries that may not reflect the true spatial structure and evolution of atmospherically driven renewable resource deficits.

This work presents a spatio-temporal characterization of renewable energy droughts across Europe using gridded fields, with the aim of identifying how these events emerge, persist, and propagate. The analysis is based on 70+ years of ERA5 reanalysis data over the North Atlantic–European sector and focuses on compound low-wind and low-solar conditions. Renewable energy droughts are identified using threshold-based methods applied consistently across the grid.

By adopting a gridded perspective, this study moves beyond country-based assessments to capture the physical footprint of renewable energy drought events as shaped by atmospheric variability. In particular, the analysis examines the displacement, extent, and persistence of these compound deficits, as well as their relation to large-scale atmospheric circulation. This provides a framework for assessing whether renewable energy droughts remain localized, propagate across regions, or organize into broader structures relevant to pan-European energy balancing.

Ultimately, this work aims to provide a physically grounded view of high-impact renewable energy droughts in Europe and of the atmospheric processes underlying their evolution. These insights are relevant for the design and resilience assessment of highly interconnected electricity systems, particularly in evaluating the extent to which a European supergrid may mitigate, or remain vulnerable to, widespread and persistent renewable energy droughts.